Field of the Invention
The present invention relates to touch sensitive devices, in particular to a capacitive touch panel and a method for producing the same.
Description of the Related Art
Touch panels have been developed rapidly since their first emergence, and now the touch panels are widely applied to varieties of appliances, such as LCD monitors, cell phones, game machines, and so on.
Now, there are many kinds of touch panels, and capacitive-type touch panels are the most popular use in the market. A conventional capacitive touch panel generally includes a cover substrate for protection, two capacitive sensing layers spaced from each other by an insulation medium, and two fabrication substrates supporting each of the capacitive sensing layers respectively. Such construction at least has three substrates for different functions, but that would make the touch panel become very thick.
One way to minimize the thickness of the capacitive touch panel is to use a single capacitive sensing layer in the touch panel. FIG. 37 illustrates a schematic plan view of a conductor pattern structure of a conventional capacitive touch panel. The conductor pattern structure is a single conductive layer including first-axis conductor assemblies (such as first-axis conductor assembly 22) and second-axis conductor assemblies (such as second-axis conductor assembly 24). The single conductive layer is superposed on a cover substrate 10 directly instead of on a fabrication substrate.
The first-axis conductor assembly 22 includes adjacent conductor cells (such as conductor cells 222, 224 shown in FIG. 37) connected by conduction lines (such as conduction line 226). The second-axis conductor assembly 24 also includes adjacent conductor cells (such as conductor cells 242, 244 shown in FIG. 37) connected by conduction lines (such as conduction line 246). There are insulation layers (like insulation layer 30 shown in FIG. 37) set between the conduction lines of the first-axis conductor assemblies and the conduction lines of the second-axis conductor assemblies. But in such arrangement of the conductor assemblies, there are gaps (like gap 112) between the first-axis conductor assemblies and the second-axis conductor assemblies.
FIG. 38 is a schematic principle view showing the light transmitting path taken along a cross-section line A-A′ in FIG. 37. Parts of incident rays from outside (like incident rays 102) are only reflected from the surface of the cover substrate 10, generating reflected rays 104. Parts of incident rays from outside (like incident rays 106) are reflected from both the surface of the cover substrate 10 and the surface of the conductor assemblies (such as conductor assemblies 224 shown in FIG. 37), generating reflected rays 108 and reflected rays 110.
The cover substrate 10 and the conductive layer are made from different materials, for example, the cover substrate 10 is made from glass and the conductive layer is made from ITO (indium tin oxide), so the refractive index of the cover substrate 10 is different from that of the conductive layer. Thus the different ways that the reflected rays are generated from different part of the touch panel will make the two layer look different and let users readily see the conductor assemblies under the cover substrate.
Thus, it is desired to provide a capacitive touch panel having a single capacitive sensing layer that overcomes the above drawbacks of the conventional capacitive touch panel.